Boo joker, losing way (4)
I believe the answer is:
jeer
'boo' is the definition.
(I've seen this in another clue)
'joker losing way' is the wordplay.
'joker' becomes 'jester' (I've seen this before).
'losing' suggests deleting specific letters.
'way' becomes 'st' (abbreviation for street).
'jester' with 'st' taken out is 'JEER'.
(Other definitions for jeer that I've seen before include "Rudely mocking remark" , "Mock publicly" , "Tease" , "Henry ---, Richard II's enemy, successor" , "Scoff, deride, mock" .)